Sprinklers are commonly used for the irrigation of landscape and vegetation. In a typical irrigation system, various types of sprinklers are used to distribute water over a desired area, including rotating stream type and fixed spray pattern type sprinklers. One type of irrigation sprinkler is the rotating deflector or so-called micro-stream type having a rotatable vaned deflector for producing a plurality of relatively small water streams swept over a surrounding terrain area to irrigate adjacent vegetation.
Rotating stream sprinklers of the type having a rotatable vaned deflector for producing a plurality of relatively small outwardly projected water streams are known in the art. In such sprinklers, one or more jets of water are generally directed upwardly against a rotatable deflector having a vaned lower surface defining an array of relatively small flow channels extending upwardly and turning radially outwardly with a spiral component of direction. The water jet or jets impinge upon this underside surface of the deflector to fill these curved channels and to rotatably drive the deflector. At the same time, the water is guided by the curved channels for projection outwardly from the sprinkler in the form of a plurality of relatively small water streams to irrigate a surrounding area. As the deflector is rotatably driven by the impinging water, the water streams are swept over the surrounding terrain area, with the range of throw depending on the flow rate of water through the sprinkler, among other things.
In rotating stream sprinklers and in other sprinklers, it is desirable to control the arcuate area through which the sprinkler distributes water. In this regard, it is desirable to use a sprinkler head that distributes water through a variable pattern, such as a full circle, half-circle, or some other arc portion of a circle, at the discretion of the user. Traditional variable arc sprinkler heads suffer from limitations with respect to setting the water distribution arc. Some have used interchangeable pattern inserts to select from a limited number of water distribution arcs, such as quarter-circle or half-circle. Others have used punch-outs to select a fixed water distribution arc, but once a distribution arc was set by removing some of the punch-outs, the arc could not later be reduced. Many conventional sprinkler heads have a fixed, dedicated construction that permits only a discrete number of arc patterns and prevents them from being adjusted to any arc pattern desired by the user.
Other conventional sprinkler types allow a variable arc of coverage but only for a limited arcuate range. Because of the limited adjustability of the water distribution arc, use of such conventional sprinklers may result in overwatering or underwatering of surrounding terrain. This is especially true where multiple sprinklers are used in a predetermined pattern to provide irrigation coverage over extended terrain. In such instances, given the limited flexibility in the types of water distribution arcs available, the use of multiple conventional sprinklers often results in an overlap in the water distribution arcs or in insufficient coverage. Thus, certain portions of the terrain are overwatered, while other portions are not watered at all. Accordingly, there is a need for a variable arc sprinkler head that allows a user to set the water distribution arc along a substantial continuum of arcuate coverage, rather than several models that provide a limited arcuate range of coverage.
It is also desirable to control or regulate the throw radius of the water distributed to the surrounding terrain. In this regard, in the absence of a flow rate adjustment device, the irrigation sprinkler will have limited variability in the throw radius of water distributed from the sprinkler, given relatively constant water pressure from a source. The inability to adjust the throw radius results both in the wasteful watering of terrain that does not require irrigation or insufficient watering of terrain that does require irrigation. A flow rate adjustment device is desired to allow flexibility in water distribution and to allow control over the distance water is distributed from the sprinkler, without varying the water pressure from the source. Some designs provide only limited adjustability and, therefore, allow only a limited range over which water may be distributed by the sprinkler.
In addition, in previous designs, adjustment of the distribution arc has been regulated through the use of a hand tool, such as a screwdriver. The hand tool may be used to access a slot in the top of the sprinkler cap, which is rotated to increase or decrease the length of the distribution arc. The slot is generally at one end of a shaft that rotates and causes an arc adjustment valve to open or close a desired amount. Users, however, may not have a hand tool readily available when they desire to make such adjustments. It would be therefore desirable to allow arc adjustment from the top of the sprinkler without the need of a hand tool. It would also be desirable to allow the user to depress and rotate the top of the sprinkler to directly actuate the arc adjustment valve, rather than through an intermediate rotating shaft.
Accordingly, a need exists for a truly variable arc sprinkler that can be adjusted to a substantial range of water distribution arcs. In addition, a need exists to increase the adjustability of flow rate and throw radius of an irrigation sprinkler without varying the water pressure, particularly for rotating stream sprinkler heads of the type for sweeping a plurality of relatively small water streams over a surrounding terrain area. Further, a need exists for a sprinkler head that allows a user to directly actuate an arc adjustment valve, rather than through a rotating shaft requiring a hand tool, and to adjust the throw radius by actuating or rotating an outer wall portion of the sprinkler head. Moreover, there is a need for improved concentricity of the arc adjustment valve, uniformity of water flowing through the valve, and a lower cost of assembly. Also, because sprinklers may become clogged with grit or other debris, there is a need for a variable arc sprinkler that allows for convenient flushing of debris from the sprinkler.